Originální popis anglicky:
ungetwc - push back a wide character onto a FILE stream
Návod, kniha: Linux Programmer's Manual
#include <wchar.h>
wint_t ungetwc(wint_t wc, FILE *stream);
The
ungetwc function is the wide-character equivalent of the
ungetc function. It pushes back a wide character onto
stream and
returns it.
If
wc is WEOF, it returns WEOF. If
wc is an invalid wide
character, it sets
errno to
EILSEQ and returns WEOF.
If
wc is a valid wide character, it is pushed back onto the stream and
thus becomes available for future wide character read operations. The
file-position indicator is decremented by one or more. The end-of-file
indicator is cleared. The backing storage of the file is not affected.
Note:
wc need not be the last wide character read from the stream; it can
be any other valid wide character.
If the implementation supports multiple push-back operations in a row, the
pushed-back wide characters will be read in reverse order; however, only one
level of push-back is guaranteed.
The
ungetwc function returns
wc when successful, or WEOF upon
failure.
ISO/ANSI C, UNIX98
fgetwc(3)
The behaviour of
ungetwc depends on the LC_CTYPE category of the current
locale.